In most diesel engine systems there is a filter device through which fuel must flow to reach the engine. When the engine apparatus is subjected to temperatures in the region of zero degrees Fahrenheit and lower, there is a tendency for ice crystals and wax to form in the diesel fuel. Such conditions cause clogging of the fuel filter device.
Another problem which exists in a conventional diesel engine apparatus relates to the fact that some of the fuel pumped to the engine is not used and the excess fuel which flows from the engine contains a small quantity of gas which is ordinarily vented from the fuel in the fuel tank as the excess fuel returns to the fuel tank.
Various methods have been employed in an attempt to overcome these problems. For example, the conventional No. 2 diesel fuel oil is mixed with No. 1 fuel oil. This has not been found to be satisfactory and adds to the expense of the fuel. U.S. Pat. Nos. 2,881,828 and 3,472,214 show the use of heat exchanger devices to heat the fuel. However, such devices may not provide heat to the fuel until a significant period of time has elapsed, and therefore fuel filter clogging may occur with initial operation.
U.S. Pat. No. 3,768,454 shows the use of a fuel tank which has a mixing zone with a temperature responsive valve controlling flow of fuel with respect to the mixing zone. Such a system requires a special fuel tank.
It is therefore an object of this invention to provide a diesel fuel control valve and system which provides fuel to a diesel engine at a proper temperature when the diesel engine apparatus is exposed to substantially any outdoor temperature, either cold or warm.
It is another object of this invention to provide such a diesel fuel control valve and system which does not require a special fuel tank.
It is another object of this invention to provide such a diesel engine fuel control valve and system which does not employ a heat exchanger device.
It is another object of this invention to provide such a diesel fuel control valve and system which can be easily and readily installed in an existing diesel engine apparatus.
It is another object of this invention to provide such a diesel engine control valve and system which is relatively small in physical size.
It is another object of this invention to provide such a diesel engine control valve and system by which gas is automatically removed from the liquid fuel.
Other objects and advantages of the diesel fuel control valve and system of this invention reside in the construction and arrangement of parts, the combination thereof, the method of manufacture, and the mode of operation, as will become more apparent from the following description.